FIG. 1A illustrates a conventional tray 100 for transporting disk drive components. Tray 100 can be assembled into a stack by attaching a clip onto protrusion 20 and lip 13. Such a clip 15 is shown in FIG. 1B. To properly secure the stack 30 of FIG. 1B, it is necessary to attach clip 15 to both sides of the stack. The disadvantages of a separate clip is that it can be easily misplaced and it has a limited stacking capacity. Only four trays can be secured in a stack with the prior art clip 15. Clip 15 has a fixed height. Consequently, the number of trays that can be secured in a stack is always limited to the parameters of clip 15. A need therefore exists for securing a stack of trays without having to use detachable clips.